1. Field of the Invention
The present invention relates to a nucleic acid amplification reaction vessel used for amplifying nucleic acid using polymerase chain reaction, and a method of manufacturing the nucleic acid amplification reaction vessel.
2. Background Art
Recently, technology related to genetic information has been actively developed. Especially in a medical field, genes related to diseases have been analyzed to allow curing of the diseases at molecule level. Genetic diagnosis allows a tailor-made medical care corresponding to an individual patient. In a drug manufacturing field, genetic information is used to identify protein molecules of antibody or hormone, and the protein molecules are used as chemicals.
In agricultural and food fields, also, products using much genetic information are manufactured.
One of the most important methods is amplification reaction of nucleic acid in the technology related to genetic information. A polymerase chain reaction method is technology of largely amplifying only a specific part of a gene, and is employed in a broad range such as study of molecular biology or the like, medical microbiology, clinical diagnosis of genetic disorders, and legal medicine. In genetic diagnosis technology especially in a clinical field, further speedy analysis is desired, and high throughput technology is desired to be developed in the polymerase chain reaction method.
The polymerase chain reaction method has the following processes:
(1) a thermal deforming process of dissociating double-strand DNA (deoxyribonucleic acid) to single-strand DNA;
(2) an annealing process of binding primers; and
(3) an elongation reaction process of elongating DNA with polymerase.
The three processes are generally defined as one cycle, and these processes are performed by 30 to 35 cycles. Japanese Patent Unexamined Publication No. S62-000281 discloses the following treatment conditions: (1) a thermal deforming process is performed at 94° C. for one minute; (2) an annealing process is performed at 50° C. to 60° C. for one minute; and (3) an elongation reaction process is performed at 72° C. for 1 to 5 minutes.
Japanese Patent Unexamined Publication No. 2002-207031 discloses a vessel or a chip used for the polymerase chain reaction. For example, a groove for holding a capillary is formed in an upper substrate, and the capillary is disposed and bonded between the upper substrate and a lower substrate. Thus, a sample containing nucleic acid to be amplified can be inserted into the capillary, and the temperature of the capillary is controlled to amplify the nucleic acid in the sample.
A device for speeding up the polymerase chain reaction is also developed. LightCycler manufactured by Loche uses hot air as a heat source, and the sample is supplied to a vessel formed of a glass capillary, for speeding up. SmartCycler® manufactured by Cepheid uses a dedicated polypropylene-made tube having a thin tube wall to speed up the polymerase chain reaction.
However, the polymerase chain reaction requires 30 or more repetitions of temperature variation by about 40° C. In a conventional device used for the polymerase chain reaction, the sample is supplied to a polypropylene-made tube and simultaneously an aluminum block is used to increase temperature, so that treatment time not less than several hours is required for completing the polymerase chain reaction.
In the method disclosed by Japanese Patent Unexamined Publication No. 2002-207031, the capillary is trapped in the upper and lower substrates, so that some increase of thermal conductivity can be expected. However, the capillary, the upper substrate, and the lower substrate are individually formed, and then bonded using an adhering technology. In this case, a heat barrier made of adhesive material or the like can be formed between the upper or lower substrate and the capillary to decrease the thermal conductivity, and fast increase or decrease of the temperature can be disadvantageously disturbed.
A device using hot air as the heat source allows speeding up, but even then treatment time not less than tens of minutes is required.
Any of conventional technologies uses a dedicated vessel such as a capillary to aim to speeding up. Therefore, a pretreatment for the polymerase chain reaction, for example extraction of DNA from blood, must be performed in a batch method, so that handling of the sample becomes complicated.